Tag: Ham Radio

The ARRL describes Amateur Radio as follows:“Amateur Radio (ham radio) is a popular hobby and service that brings people, electronics and communication together. People use ham radio to talk across town, around the world, or even into space, all without the Internet or cell phones. It’s fun, social, educational, and can be a lifeline during times of need.”

You can set up a ham radio station anywhere!

On a beach…

…in your overland rig

…or at home.

Although Amateur Radio operators get involved for many reasons, they all have in common a basic knowledge of radio technology and operating principles, and pass an examination for the FCC license to operate on radio frequencies known as the “Amateur Bands.” These bands are radio frequencies allocated by the Federal Communications Commission (FCC) for use by ham radio operators.”

What Are The License Classes:

In the United States there are three classes of Amateur Radio Operator Licenses (Ham)

Technician Class

General Class

Extra Class

Each Class license increases your privileges on the air.

Primarily the Technician Class license is for VHF/UHF communications, which work well for regional contacts. VHF (2M) and UHF (70CM) are the two most common forms of mobile ham radio communications equipment. Simplex these operate line of sight, which is to say 5-10 miles over flat level terrain.

The General Class license opens up 90% of the HF bands for you. These bands work for around-the-world communications, even with low power and modest antennas. As an example, while driving on Hwy 71 in Austin, Texas, I was able to carry on a conversation with a HAM outside Moscow, in Russia.

Finally the Extra Class license gives you the last small piece of the pie. Primarily these are edges of the bands which more closely overlap with other nations band allocations opening up more opportunities to talk to HAMs from other countries.

How Can You Get Licensed:

Ham Radio Clubs across the country offer testing sessions every month. The ARRL (Amateur Radio Relay League) provides a tool to help you locate Amateur Radio License Exams in your area. TEST FINDER

Tests cost around $15 to take. If you pass the Technician the testing site will let you take your General test in the same sitting for free. If you pass your General test, they will let you take the Extra for free in the same sitting. So with proper preparation it is possible to go from unlicensed to Extra in one day.

Once you pass a test, your license is good for 10 years, at which point you renew your license for free. You do not need to take any further tests.

Training/Study Materials:

There are books from Gordon West to help you prepare for the tests. I found Gordon West’s teaching style in his AUDIO CD Programs to be very compatible with my learning style.

You can take Practice tests for all three license classes here: QRZ.com (free registration required)
Each requires a score of greater than 70% to pass. If you are regularly scoring around 85% on practice tests, you are ready for the real thing!

This is just and FYI for those that may not know. And the bottom line first…

You may not use a VHF radio in the United States without a valid FCC-issued license or Amateur radio license. Use of VHF radios in Mexico is allowed during the SCORE Baja race, and subject to local regulations.

Here is an example of VHF itinerant/business band frequencies commonly used in the Baja Races. Operators of the frequencies are licensed. If you transmit on frequencies you’re not licensed for, then you are operating a pirate radio station, and are subject to fines and equipment confiscation. 🙁

I have observed a trend of individuals buying ham radios and modifying them to transmit outside the ham bands. That in of itself is not a problem. But if you key up outside the ham bands–that’s illegal, and you put yourself at risk for fines and confiscation (more on that below). Also problematic is buying business band radios and operating them on frequencies without the requisite license.

Some people think the FCC enforcement is a toothless tiger, and nothing bad will happen to them, and maybe that’s all true. But people should know that there are risks involved. And that’s why I took the time to write this, as to inform people. I don’t care what you do in the desert as long as it doesn’t hurt or interfere with other people.

Also, I think it’s incredibly foolish for people to post in a public forum the date, time, and place of a future meet and the illegal frequency they’ll be communicating on. :laugh:

If you have questions about Race radios, I have found this shop to be very helpful. PCI Race Radios. As it turns out they are the itinerant and properly licensed operator of the Weatherman frequency.

Finally, WB4CS a licensed amateur radio operator wrote the FCC asking a question and the answer is relevant to the topic here.

Here is what the FCC wrote:

FCC response per WB4CS said:
As you note, “The rules are clear that in order to use Part 90 or 95 spectrum, the operator must have the correct licensing and certified radios to use those services.” The debate you are referring to, therefore, comes down to “How can we get around the rules?” The answer is, “You can’t.” We will be happy to relieve you of thousands or tens of thousands of dollars and your amateur radio license if you transmit on channels you are not licensed to transmit on.

Here are some example mobile transceiver options. Each of these is a dual band radio (2m and 70cm). Also each of these has a detachable, or detached, control head. I’ll add a note next to each with additional features.

Kenwood, Icom, and Yaesu are regularly referred to as “The Big Three.” They are the ham radio equivalent of Ford, GM, and Chrysler. There are other brands, but if we’re focusing on high quality, reliable equipment, these are the brands that are going to receive all of my attention.

Digital Modes
On the topic of Digital Modes. There are currently three competing standards. (Think VHS vs Betamax) or for you youngsters (BluRay vs HD DVD)

Yaesu has developed and released a system called Fusion. It’s based on C4FM.
Icom has had a system called D-Star for the last 10 years.
Motorola Has a system referred to as DMR, or MotoTRBO.

If my Crystal Ball is tuned properly, I think Yaesu’s Fusion system is going to end up being the winning technology for most average hams. I make no promises that this is correct. However looking at how unsuccessful Icom has appeared to be with D-Star, I think it’s unlikely they’re going to win the battle.

I think the EMCOM (Emergency Communication) crowd is going to flock to MotoTRBO/DMR. In large part because many of the ARES/RACES Emergency Communications types also work with Police/Fire/Search & Rescue Teams and are carrying Motorola radios already.

I didn’t mention Motorola radios above in my list. Motorola builds some exceptionally high quality equipment. However it’s all designed for use as Business Band Radios. They work fine in the Amateur Radio Service, and it’s legal for a Ham to use them as such. However I think anyone leaning toward a Motorola, is already experienced enough that they’re not looking for any advice from me. 🙂

Mobile Radio Gear: (VHF/UHF only in this segment)
Radios for Overlanding fall into two major categories. Handheld Transceivers (HTs) and Mobile Radios.

Handheld Transceivers are effectively “Walkie Talkies” and can run from as inexpensive as $35 per unit for a Baofeng UV-5R all the way up to several hundred dollars for a top of the line Yaesu/Icom/Kenwood digital HT, like this Yaesu FT2DR. HTs typically offer several power settings, with Low being ~ 0.5W, medium being 1-2W, and high being 5W. At 5W the radios tend to get hot while transmitting a lot, and the batteries don’t last long. (It’s worth noting a CB maxes out at 4W in the United States…)

Mobile Radios come in three major varieties, and then have a host of options. The three major types of mobile VHF/UHF rig are:
Single Band (usually 2M)
Dual Band (usually 2M/70CM)
Dual Band CrossBand Repeater (usually 2M/70CM)
The single band radios are exactly what they sound like. These radios operate within a single band, which usually means 2M, although they don’t have to. These usually, but not always, output between 5w on Low Power and upwards of 75W on High.

A dual band radio is virtually identical to the single band radio, except you can select between two bands. This means if you’re in a small group, and if everyone has dual band, you can select which band you want to use. The 2M band is the most popular band in the world. If you’re looking for a quiet place to talk within your caravan, you might choose as a group to move to 70CM for instance.

Finally we have CrossBand Repeaters. These are also dual band radios, but they have two receivers in them, rather than one. This means they act in many ways as if you have TWO radios at the same time in your vehicle. These include a special mode of operation though, that allow you to “connect” the 2M radio to the 70CM radio. Thus, anything received on the 70CM side will be instantly re-transmitted on the 2M side. And anything received on the 2M side, will be re-transmitted on the 70CM side. When coupled with an HT, this can allow you to use the HT on 0.5W on 70cm, but communicate with a remote station using the 50-75W 2M transmitter in your vehicle. (Ask me about “Red River Gorge” in Kentucky sometime.)

Digital Mobile Radios Another newer entry into the Mobile, and HT ham radio market is Digital radios. These all operate normal FM like the others listed, however they include some form of digital encoding. Right now there are no “standards” so each vendor has their own competing protocols. Yaesu appears to have the most widely adopted system with C4FM FDMA and their Fusion Repeaters. This is a fairly in depth discussion on its own, and I’d be happy to field questions to the best of my ability but won’t muddy the waters here.

Like everything else in life, in many ways you do get what you pay for. I personally intend to pick up a few (5?) UV-5R radios to keep in a Pelican case in the truck for dire emergencies but wouldn’t personally trust them as a primary radio. Ham radio is like a lot of hobbies. There are many different ways to participate and enjoy the hobby. I’ve hardly scratched the surface here. I, and I suspect the rest of the Hams on Overland Bound, would be happy to field any discussion on the hobby you might have.

When my wife and I went to Natural Bridge in Kentucky back in 2007 she wrote the following diary note to go with this photo.

While hiking in the park, I noticed that the nearest Cell phone reception was 11 miles down the road from where we were.

There’s also a warning on the bulletin board near virtually every trail head: “Every year, about forty-five people fall from these cliffs. One or two usually result in death. Once contact is made with emergency personnel, it will take at least thirty minutes for someone to arrive. Many falls result in spinal injuries, so the person who comes to find you must wait for the EMTs to arrive to remove you safely – another thirty minute wait. Unpacking all the equipment, bundling you up securely, and getting you back to the emergency vehicle can take over an hour. It’s a forty-five minute drive to the nearest hospital. In other words, if you fall, it could be about three hours before you receive proper medical treatment. And that’s after you actually manage to contact someone.”

I ensured that from my car, parked in the lot I could reach the local 2M repeater in the next town over. I then turned on the cross band repeater, and set the 70CM side of the car, and my HT to match one another. This gave me an instant link to “town” and several times while hiking, I verified that I could both hear the repeater in town, and still communicate with the hams there. (all while using 0.5W) There’s nothing like eliminating the time to get to a place you can call for help.

This post is mostly taking details from the above two sites, and merging them into a single, easy for me to find set of notes on how to get Xastir working with the RTL-SDR on a Debian/Ubuntu based Linux system. This will serve as the foundation of a future version that will be deployed on a Raspberry Pi3-B, configured with a 7″ screen, and installed in my truck for mobile APRS tracking.

Here’s a good screen capture of my Xastir map after running for about an hour.

Finally we need to launch xastir, and tell it how to find our APRS data. Launch xastir, and after the intial setup click: Interface –> Interface Control –> Add –> Internet Server Then select “Activate on Startup”
Deselect “Allow Transmitting (Your RTL-SDR is only a receiver afterall)” Set the host to “Localhost” Then click OK.
Finally you will need to select your new Internet server from the list, and click Start, or just click Start All.

Here’s a “Potato Quality” photo of my Thinkpad X201i running Xastir, with a few stations plotted on the map.

There are several Weather stations in the area I can receive directly as well.

If everything went well, you should start seeing stations appear on your map. Happy APRSing.

In part 2 of my RTL-SDR powered APRS series I’m going to discuss how I configured an IGate using aprx. The first order of business however is getting the RTL-SDR to receive, and decode APRS traffic. The software I used is called multimonNG the installation of this package is pretty straight forward.

Once this is complete, we can fire up rtl_fm which we built in the part 1 and by using the Unix Pipe we are going to send the output of the receiver through multimon-ng and then onto the network. The command I’m using to start the receiver is as follows:

This opens the receiver and sets the gain to 80, on the North America APRS calling frequency of 144.390mhz, with a sample rate of 22050hz. The output of the reciever is then sent into multimon-ng which uses the AFSK1200 decoder and the -A flag tells it specifically to use the APRS format. Due to some limitations in how multimon-ng works getting the output into something usable requires interacgint with /dev/stdin. If we ended the command there, the decoded APRS packets would be displayed on the terminal for you like the following entries:

The last three lines in the above block are actual APRS packets received by the RTL-SDR, decoded by multimon-ng, and displayed on the terminal. This is fun but ultimately I want to push those messages into the APRS network. For this I need to add an IGate like aprx. Installing aprx is much like everything else we’ve done so far.

Next we need to configure aprx. For this edit /etc/aprx.conf. The file is well commented, and should be pretty straight forward. In my case, I set the following fields:

mycall

myloc

passcode

server

filter

Then in the section I set aprx up to use a TCP socket.

<interface>
tcp-device localhost 6666 TNC2
</interface>

From this point we need to adjust the line we used to start the receiver, as aprx is listening to a network socket, and not looking at a terminal for packets. So we go back to our initial command and pipe the output from /dev/stdin into netcat and are left with the following:

Recently I purchased a RTL-SDR to play with. These are dirt cheap on Amazon or Ebay usually to the tune of $10 or less shipped to your door. I had a few different ideas of how I would use this, but first on my list was to build an APRS receiver & decoder.

First I had to figure out how to get my RTL-SDR working on Linux. First we need to install a bunch of pre-requisite packages on our Debian/Ubuntu system.

One of the great strengths of Amateur Radio is how flexible the hobby is. One type of operation that is very interesting for the Overlander is called APRS. (Amateur Position Reporting System) APRS takes raw NEMA2 data from a GPS, encodes it, and transmits it over the amateur bands. A simple APRS Transmitter/Receiver can be built by connecting an inexpensive handheld transceiver (around $35 on Amazon) to an Android Phone or Tablet with a GPS, and then installing a $4.95 piece of software called APRSdroid. This APRS site can then simultaneously transmit your coordinates, as well as display the near real-time locations of every other APRS station within receiving distance. Imagine a caravan of five vehicles, each with an small APRSdroid powered APRS system in their vehicles, with the map display turned on.

While driving through the mountains on the Rimrocker Trail my APRS transmitter was happily sending out telemetry data every 5 minutes (because I was traveling less than 60 miles per hour) or every time I had a more than a 14 degree change in direction. Because of the range 2m has while in the mountains (Line of sight from 9,000 feet is a long way.) I actually have a pretty complete picture of where we traveled.

APRS isn’t as perfect as plotting your own maps with an onboard GPS and Tracking software, but it’s kind of neat to know that the family of one of the guys with us could fairly reliably track our progress through the Rocky Mountains.